The Raven/Gresley A8 Pacific Tank Locomotives

During the mid-1920s, A5 4-6-2Ts were ordered for the North East Area to
work alongside the H1s.
It quickly became apparent that the A5s had better adhesion due to its
six-coupled driving wheels. Hence in 1931,
H1 No. 2162 was rebuilt as a 4-6-2T and
given the A8 classification.
After a series of trials throughout the North East Area, all of the remaining
H1s were rebuilt as A8 4-6-2Ts between
1933 and 1936.

During the process of rebuilding, the boiler was modified to include a
Robinson-type superheater rather than
the original Schmidt superheater. In 1935, further modifications resulted in the A8 boiler being
interchangeable with the
A6, A7, A8,
H1, and
T1 classes.

The rebuilt A8s could easily work the heavy suburban traffic and long distance coastal trains on
which they were put to work. They were also welcome replacements for the aging
G5 0-4-4Ts which had been
working these services.
Allocations of the 45 locomotives were split between the North East / Newcastle area, the Yorkshire Coast
(Whitby and Scarborough), Hull, and Leeds (Neville Hill).

Diesel railcars were rapidly introduced during the 1950s, and the A8s quickly became surplus to
requirements. Withdrawals started in 1957, and the A8 was extinct by the end of 1960.

Technical Details

Cylinders (x3):

16.5x26in.

Motion:

Stephenson

7.5in. piston valves

Boiler:

Max. Diameter:

4ft 9in

Pressure:

175psi

Diagram No.:

63

Heating Surface:

Total:

1084.6 sq.ft.

Firebox:

124 sq.ft.

Superheater:

191.134 sq.ft.

Tubes:

680 sq.ft. (131x 1.75in)

Flues:

280.6 sq.ft. (18x 5.25in)

Grate Area:

23 sq.ft.

Wheels:

Leading:

3ft 1.25in

Coupled:

5ft 9in

Trailing:

3ft 9in

Tractive Effort:

22,940lb

(@ 85% boiler pressure)

Total Wheelbase:

33ft 3in

Length:

42ft 6in

Engine Weight:

(full)

86 tons 18cwt

Max. Axle Load:

17 tons 16cwt

Water Capacity:

2,000 gallons

Coal Capacity:

4 tons

Preservation

The last A8 was withdrawn in 1960, and none survived into preservation.